pgproxy

type BranchRefresher interface {
	RefreshBranch(ctx context.Context, name string) (addr string, err error)
}

type BranchResolver interface {
	ResolveBranch(name string) (addr string, err error)
}

type Proxy struct {
	Resolver BranchResolver
	// DialTimeout bounds the backend dial (and a forwarded cancel request's
	// exchange with the backend). Defaults to 5s.
	DialTimeout time.Duration
	// FirstByteTimeout bounds how long a new connection may stay silent before
	// sending its first byte. Real clients write immediately after connecting,
	// so this is short: it keeps idle sockets from holding a connection slot
	// for the whole StartupTimeout. Defaults to 2s.
	FirstByteTimeout time.Duration
	// StartupTimeout bounds the client's startup packets (SSL/GSS negotiation,
	// the TLS handshake and the StartupMessage), measured from accept. A client
	// that dribbles bytes is dropped after this. Defaults to 10s.
	StartupTimeout time.Duration
	// AuthTimeout bounds the rest of the startup exchange: from routing the
	// StartupMessage until the backend sends its first ReadyForQuery, which
	// covers the whole authentication exchange. The proxy enforces it itself
	// instead of relying on the branch's authentication_timeout. Defaults to
	// 30s.
	AuthTimeout time.Duration
	// MaxConns caps the number of connections handled concurrently. When the
	// cap is reached, further accepts are refused fast (connection closed)
	// rather than queued unbounded. Defaults to 256; a negative value disables
	// the cap.
	MaxConns int
	// MaxStartupsPerIP caps how many connections from one client IP may be in
	// the startup phase at once (anything before the backend's first
	// ReadyForQuery: TLS, StartupMessage, authentication, and cancel
	// requests). Authenticated sessions do not count, so one host running many
	// real sessions is not limited, but one address cannot fill MaxConns with
	// connections that never authenticate. Over the cap, new connections are
	// refused fast. Defaults to 64; a negative value disables the cap.
	MaxStartupsPerIP int
	// IdleTimeout closes an authenticated session that has seen no bytes in
	// either direction for this long, reclaiming abandoned-but-open
	// connections. It bounds reads and writes, so a peer that stops reading
	// cannot pin the session either. Defaults to 15m.
	IdleTimeout time.Duration
	// TLSConfig, when set, makes the proxy answer SSLRequest with 'S' and
	// upgrade the client connection via a server-side TLS handshake before
	// the startup message. When nil (default) SSLRequest is answered 'N' and
	// the session stays plaintext. Backend dials are always plaintext
	// (branches are local/cluster-internal).
	TLSConfig *tls.Config
	// contains filtered or unexported fields
}

type RegistryResolver struct {
	Reg *registry.Registry
	// Refresh, when set, re-reads a ready branch's address from the runtime
	// and records it if it moved (branchd wires engine.RefreshBranchEndpoint).
	// nil disables the refresh after a failed dial.
	Refresh func(ctx context.Context, name string) (string, error)
}